Purification method and purification equipment of liquid polycarbosilane

Abstract

The invention discloses a purification method of liquid polycarbosilane. The purification method comprises the following steps: preheating crude liquid polycarbosilane to 30-40 DEG C; mixing the preheated liquid polycarbosilane with a purifying agent, stirring, standing and splitting phases to obtain a water phase A containing impurities and an organic phase A containing the liquid polycarbosilane; mixing the organic phase A obtained by phase splitting with diluted hydrochloric acid, stirring, standing, and performing phase splitting to obtain a water phase B containing impurities and an organic phase B containing liquid polycarbosilane; and after the steps are repeated for 2-3 times, drying the organic phase containing the liquid polycarbosilane obtained by phase splitting by using anhydrous magnesium sulfate, filtering by using an organic filter membrane, and finally distilling to obtain the high-purity liquid polycarbosilane. The invention further discloses purification equipment used on the basis of the purification method of the liquid polycarbosilane, and the high-purity liquid polycarbosilane which is low in impurity content, good in stability and low in loss rate can be obtained.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide ceramic materials technology, specifically to a method and equipment for purifying liquid polycarbosilane. Background Technology

[0002] In recent years, with the rapid development of my country's aerospace and other fields, the new generation of aerospace vehicles has placed higher demands on high-temperature structural materials. Silicon carbide ceramic matrix composites possess excellent properties such as high-temperature strength, fracture toughness, thermal shock resistance, oxidation resistance, and ablation resistance, making them a novel strategic thermal structural material. Currently, silicon carbide ceramic matrix composites are gradually being applied to aerospace engines, spacecraft, and other equipment. Furthermore, they also have wide applications in braking systems and high-performance optical devices.

[0003] Liquid polycarbosilane, due to its good fluidity, self-crosslinking ability, high ceramic yield, and near-stoichiometric ratio of pyrolysis products, is a key precursor for the preparation of high-performance silicon carbide ceramic matrix composites. Its purity directly determines the mechanical properties and high-temperature resistance of the ceramic matrix composites obtained from subsequent pyrolysis and conversion.

[0004] Liquid polycarbosilanes are typically produced by first coupling and polymerizing chloromethylchlorosilanes under the catalysis of a Mg / THF Grignard reagent to form chlorinated polycarbosilanes. The chlorinated polycarbosilanes are then reduced with LiAlH4 to obtain liquid polycarbosilanes. However, the Mg / THF Grignard reagent coupling reaction generates magnesium impurities, and the subsequent reduction reaction with lithium aluminum hydride produces lithium and aluminum impurities. These impurities mainly remain in the crude liquid polycarbosilane as magnesium chloride, aluminum chloride, and lithium chloride. Direct use of this crude liquid polycarbosilane in the preparation of silicon carbide ceramic matrix composites would lead to defects such as pores and cracks within the ceramic, causing abnormal grain boundaries and significantly degrading the material's flexural strength, high-temperature resistance, and chemical stability. This would fail to meet the performance requirements of high-end applications such as aerospace for ceramic matrix composites. Therefore, efficient purification of crude liquid polycarbosilanes to prepare high-purity liquid polycarbosilanes is crucial for ensuring the performance of silicon carbide ceramic matrix composites.

[0005] Currently, the mainstream process for removing impurities from crude liquid polycarbosilane in the industry is the batch reactor water washing extraction method. Its core principle is to use water as an extractant to dissolve impurities such as magnesium chloride, aluminum chloride, and lithium chloride in the crude product. Simultaneously, it utilizes the compatibility of water with tetrahydrofuran (THF) to extract and remove any residual THF. However, this process faces insurmountable technical bottlenecks, specifically as follows: 1. Insufficient product purity and poor stability: The impurity removal rate of a single water wash is only ≤40%, and it is necessary to repeat the extraction 6 to 8 times to reduce the total impurity content of magnesium, lithium and aluminum to 50 to 100 ppm. Moreover, the purity fluctuates greatly between batches, which cannot meet the high purity requirements of high-end ceramic matrix composite materials for precursors. 2. High product loss rate: Multiple phase separation operations result in a loss rate of ≥8% for liquid polycarbosilane, which not only reduces the utilization rate of raw materials but also significantly increases production costs. 3. Low production efficiency: Batch operation is adopted, and the processing cycle of a single batch is as long as 36 to 48 hours, which makes it impossible to achieve continuous production. Summary of the Invention

[0006] The purpose of this invention is to provide a method and equipment for purifying liquid polycarbosilane, which is applicable to the purification of crude liquid polycarbosilane obtained after coupling with Mg / THF Grignard reagent and reduction with lithium aluminum hydride. The method yields high-purity liquid polycarbosilane with low impurity content, good stability, and low loss rate, which can be used as a core precursor for silicon carbide ceramic matrix composites and is widely used in aerospace, high-end equipment and other fields.

[0007] To achieve the above objectives, the solution of the present invention is: A method for purifying liquid polycarbosilane includes the following steps: Step 1: First, preheat the crude liquid polycarbosilane to 30~40℃; Step 2: Then, the preheated liquid polycarbosilane is mixed with the purifying agent and stirred for 30-60 min at a temperature ≤0℃ and a stirring rate of 150-200 r / min. After standing for 30-60 min, the phases are separated to obtain an aqueous phase A containing impurities and an organic phase A containing liquid polycarbosilane. The purifying agent includes a hydrocarbon organic solvent with a boiling point below 120°C and dilute hydrochloric acid, wherein the mass ratio of the hydrocarbon organic solvent to the dilute hydrochloric acid is 1:3 to 1:10, and the mass ratio of crude liquid polycarbosilane to the purifying agent is 1:1 to 1:3. Step 3: Then, the organic phase A obtained by phase separation is mixed with dilute hydrochloric acid and stirred for 10-30 min at a temperature ≤10℃ and a stirring rate of 150-200 r / min. After standing for 10-30 min, phase separation is performed to obtain an aqueous phase B containing impurities and an organic phase B containing liquid polycarbosilane. The mass ratio of organic phase A to dilute hydrochloric acid is 1:1 to 1:3. Step 4: Repeat step 3 2-3 times, then dry the organic phase containing liquid polycarbosilane obtained by phase separation with anhydrous magnesium sulfate, filter it through an organic filter membrane, and finally distill it at 60-80℃ and 0.095-0.1 MPa for 30-60 min to obtain high-purity liquid polycarbosilane.

[0008] In step 2, the hydrocarbon organic solvent is n-pentane, n-hexane, n-heptane, and petroleum ether.

[0009] In step 2, the concentration of the dilute hydrochloric acid is 2~3 mol / L.

[0010] In step 3, the concentration of the dilute hydrochloric acid is 0.5~1 mol / L.

[0011] In step 4, the pore size of the organic filter membrane is 0.45 μm.

[0012] A purification apparatus for liquid polycarbosilane includes a heating vessel for preheating crude liquid polycarbosilane, a first-stage mixing chamber for mixing the preheated liquid polycarbosilane with a purifying agent, a first-stage phase separation chamber for separating aqueous phase A and organic phase A, a second-stage mixing chamber for mixing organic phase A with dilute hydrochloric acid, a second-stage phase separation chamber for separating aqueous phase B and organic phase B, a drying vessel for drying, a filtering vessel for filtration, and a distillation vessel for distillation, all connected in sequence.

[0013] A third-stage mixing chamber and a third-stage phase separation chamber are sequentially connected between the second-stage phase separation chamber and the drying kettle.

[0014] A fourth-stage mixing chamber and a fourth-stage phase separation chamber are sequentially connected between the third-stage phase separation chamber and the drying kettle.

[0015] The heating kettle, the first mixing chamber, the second mixing chamber, the third mixing chamber, the fourth mixing chamber, and the drying kettle are all equipped with stirring devices.

[0016] By adopting the above technical solution, the purification method and purification equipment for liquid polycarbosilane of the present invention have the following beneficial effects: 1. This invention innovatively proposes a purification system of "hydrocarbon organic solvent + dilute hydrochloric acid", which precisely matches the dissolution requirements of magnesium chloride, aluminum chloride and lithium chloride impurities in crude product, while avoiding damage to the polycarbosilane molecular structure, optimizing the raw material ratio, and achieving a balance between efficient dissolution of impurities and rapid phase separation. 2. Multi-stage continuous process innovation: Breaking through the limitations of existing batch-type autoclave washing, it adopts 3-4 stages of continuous separation operation, with a processing cycle of only 3-5 hours, greatly improving efficiency; 3. High product purity and stable performance: Through the synergy of a specific purification system and multi-stage separation operation, the total impurity content of magnesium, lithium and aluminum in the system can be stably controlled at ≤50 ppm, solving the pain points of insufficient purity and poor stability of existing products; 4. Outstanding application value: The product has excellent physical and chemical properties and good compatibility with ceramic matrix composite preparation systems. As a precursor, it can significantly improve the bending strength and high temperature resistance of ceramic materials and reduce the incidence of internal defects. It can be widely used in high-end fields such as aerospace and high-end equipment, and has broad market prospects. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a purification device for liquid polycarbosilane according to the present invention.

[0018] In the picture: Heating vessel 1; First-stage mixing chamber 2; First-stage phase separation chamber 3; Second-stage mixing chamber 4; Second-stage phase separation chamber 5; Drying kettle 6; Filter vessel 7; Distillation vessel 8; Third-stage mixing chamber 9; Third-stage phase separation chamber 10; Fourth-stage mixing chamber 11; Fourth-stage phase separation chamber 12. Detailed Implementation

[0019] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0020] Example 1 A purification device for liquid polycarbosilane, such as Figure 1 As shown, the apparatus includes a heating vessel 1 for preheating crude liquid polycarbosilane, a first-stage mixing chamber 2 for mixing the preheated liquid polycarbosilane with a purifying agent, a first-stage phase separation chamber 3 for separating the phases to obtain aqueous phase A and organic phase A, a second-stage mixing chamber 4 for mixing organic phase A with dilute hydrochloric acid, a second-stage phase separation chamber 5 for separating the phases to obtain aqueous phase B and organic phase B, a drying vessel 6 for drying, a filtering vessel 7 for filtering, and a distillation vessel 8 for distillation.

[0021] Furthermore, a third-stage mixing chamber 9 and a third-stage phase separation chamber 10 are sequentially connected between the second-stage phase separation chamber 5 and the drying kettle 6.

[0022] Furthermore, a fourth-stage mixing chamber 11 and a fourth-stage phase separation chamber 12 are sequentially connected between the third-stage phase separation chamber 10 and the drying kettle 6.

[0023] Furthermore, stirring devices are provided in the heating vessel 1, the first-stage mixing chamber 2, the second-stage mixing chamber 4, the third-stage mixing chamber 9, the fourth-stage mixing chamber 11, and the drying vessel 6.

[0024] The purification method of the present invention is carried out using the purification equipment, which is a conventional multi-stage separation device in the art. The heating kettle 1, the first-stage mixing chamber 2, the first-stage phase separation chamber 3, the second-stage mixing chamber 4, the second-stage phase separation chamber 5, the third-stage mixing chamber 9, the third-stage phase separation chamber 10, the fourth-stage mixing chamber 11, the fourth-stage phase separation chamber 12, the drying kettle 6, the filtering kettle 7, and the distillation kettle 8 are all devices known in the art, and the various devices are connected by pipelines.

[0025] Example 2 A method for purifying liquid polycarbosilane includes the following steps: Step 1: First, pour the crude liquid polycarbosilane into heating vessel 1 and preheat it to 30°C; Step 2: Then, the preheated liquid polycarbosilane and the purifying agent are introduced into the first-stage mixing chamber 2 at a mass ratio of 1:2 and mixed. The mixture is stirred for 30 min at a temperature ≤0℃ and a stirring rate of 200 r / min. The resulting mixture is then introduced into the first-stage phase separation chamber 3 and allowed to stand for 30 min. The phases are separated to obtain an aqueous phase A containing impurities and an organic phase A containing liquid polycarbosilane. The purifying agent includes n-hexane at a mass ratio of 1:5 and 3 mol / L dilute hydrochloric acid. Step 3: Then, the organic phase A obtained from the phase separation is mixed with 0.8 mol / L dilute hydrochloric acid in a mass ratio of 1:2 in the second-stage mixing chamber 4. The mixture is stirred for 10 min at a temperature ≤5℃ and a stirring rate of 200 r / min. The resulting mixture is then passed into the second-stage phase separation chamber 5 and allowed to stand for 10 min. The phases are separated to obtain an aqueous phase B containing impurities and an organic phase B containing liquid polycarbonylsilane. Repeat step 3, and mix the organic phase B obtained from the phase separation with 0.8 mol / L dilute hydrochloric acid in the third stage mixing chamber 9 at a mass ratio of 1:2. Stir for 10 min at a temperature ≤5℃ and a stirring rate of 200 r / min. The resulting mixture is then passed into the third stage phase separation chamber 10 and allowed to stand for 10 min. The phases are separated to obtain an aqueous phase C containing impurities and an organic phase C containing liquid polycarbonylsilane. Repeat step 3 again, and mix the organic phase C obtained from the phase separation with 0.8 mol / L dilute hydrochloric acid in the fourth stage mixing chamber 11 at a mass ratio of 1:2. Stir for 10 min at a temperature ≤5℃ and a stirring rate of 200 r / min. The resulting mixture is then passed into the fourth stage phase separation chamber 12 and allowed to stand for 10 min. The phases are separated to obtain an aqueous phase D containing impurities and an organic phase D containing liquid polycarbonylsilane. Step 4: Then, the organic phase D containing liquid polycarbosilane obtained by phase separation is passed into the drying kettle 6 and dried with anhydrous magnesium sulfate. After being filtered through an organic filter membrane with a pore size of 0.45 μm in the filter kettle 7, it is finally passed into the distillation kettle 8 and distilled at 60℃ and a vacuum of 0.095 MPa for 60 min to obtain high-purity liquid polycarbosilane. The aqueous phases obtained from phase separation in steps 2 and 3 are collected and then successively neutralized with sodium hydroxide and treated in a high-gravity bed before being discharged.

[0026] Example 3 A method for purifying liquid polycarbosilane includes the following steps: Step 1: First, pour the crude liquid polycarbosilane into heating vessel 1 and preheat it to 35°C; Step 2: Then, the preheated liquid polycarbosilane and the purifying agent are introduced into the first-stage mixing chamber 2 at a mass ratio of 1:3 and mixed. The mixture is stirred for 45 min at a temperature ≤0℃ and a stirring rate of 180 r / min. The resulting mixture is then introduced into the first-stage phase separation chamber 3 and allowed to stand for 45 min. The phases are separated to obtain an aqueous phase A containing impurities and an organic phase A containing liquid polycarbosilane. The purifying agent includes n-heptane and 3 mol / L dilute hydrochloric acid at a mass ratio of 1:3. Step 3: Then, the organic phase A obtained from the phase separation is mixed with 1.0 mol / L dilute hydrochloric acid in a mass ratio of 1:3 in the second-stage mixing chamber 4. The mixture is stirred for 20 min at a temperature ≤2℃ and a stirring rate of 180 r / min. The resulting mixture is then passed into the second-stage phase separation chamber 5 and allowed to stand for 20 min. The phases are separated to obtain an aqueous phase B containing impurities and an organic phase B containing liquid polycarbonylsilane. Repeat step 3, and mix the organic phase B obtained from the phase separation with 1.0 mol / L dilute hydrochloric acid in the third stage mixing chamber 9 at a mass ratio of 1:3. Stir for 20 min at a temperature ≤2℃ and a stirring rate of 180 r / min. The resulting mixture is then passed into the third stage phase separation chamber 10 and allowed to stand for 20 min. The phases are separated to obtain an aqueous phase C containing impurities and an organic phase C containing liquid polycarbonylsilane. Repeat step 3 again, and mix the organic phase C obtained from the phase separation with 1.0 mol / L dilute hydrochloric acid in the fourth stage mixing chamber 11 at a mass ratio of 1:3. Stir for 20 min at a temperature ≤2℃ and a stirring rate of 180 r / min. The resulting mixture is then passed into the fourth stage phase separation chamber 12 and allowed to stand for 20 min. The phases are separated to obtain an aqueous phase D containing impurities and an organic phase D containing liquid polycarbonylsilane. Step 4: Then, the organic phase D containing liquid polycarbosilane obtained by phase separation is passed into the drying kettle 6 and dried with anhydrous magnesium sulfate. After being filtered through an organic filter membrane with a pore size of 0.45 μm in the filter kettle 7, it is finally passed into the distillation kettle 8 and distilled for 30 min at 80℃ and a vacuum of 0.095 MPa to obtain high-purity liquid polycarbosilane. The aqueous phases obtained from phase separation in steps 2 and 3 are collected and then successively neutralized with sodium hydroxide and treated in a high-gravity bed before being discharged.

[0027] Example 4 A method for purifying liquid polycarbosilane includes the following steps: Step 1: First, pour the crude liquid polycarbosilane into heating vessel 1 and preheat it to 38°C; Step 2: Then, the preheated liquid polycarbosilane and the purifying agent are introduced into the first-stage mixing chamber 2 at a mass ratio of 1:2 and mixed. The mixture is stirred for 60 min at a temperature ≤0℃ and a stirring rate of 150 r / min. The resulting mixture is then introduced into the first-stage phase separation chamber 3 and allowed to stand for 60 min. The phases are separated to obtain an aqueous phase A containing impurities and an organic phase A containing liquid polycarbosilane. The purifying agent includes petroleum ether (boiling point 90~120℃) and 2.5 mol / L dilute hydrochloric acid at a mass ratio of 1:3. Step 3: Then, the organic phase A obtained from the phase separation is mixed with 0.5 mol / L dilute hydrochloric acid in a mass ratio of 1:2 in the second-stage mixing chamber 4. The mixture is stirred for 30 min at a temperature ≤8℃ and a stirring rate of 150 r / min. The resulting mixture is then passed into the second-stage phase separation chamber 5 and allowed to stand for 30 min. The phases are separated to obtain an aqueous phase B containing impurities and an organic phase B containing liquid polycarbonylsilane. Repeat step 3, and mix the organic phase B obtained from the phase separation with 0.5 mol / L dilute hydrochloric acid in the third stage mixing chamber 9 at a mass ratio of 1:2. Stir for 30 min at a temperature ≤8℃ and a stirring rate of 150 r / min. The resulting mixture is then passed into the third stage phase separation chamber 10 and allowed to stand for 30 min. The phases are separated to obtain an aqueous phase C containing impurities and an organic phase C containing liquid polycarbonylsilane. Repeat step 3 again, and mix the organic phase C obtained from the phase separation with 0.5 mol / L dilute hydrochloric acid in the fourth stage mixing chamber 11 at a mass ratio of 1:2. Stir for 30 min at a temperature ≤8℃ and a stirring rate of 150 r / min. The resulting mixture is then passed into the fourth stage phase separation chamber 12 and allowed to stand for 30 min. The phases are separated to obtain an aqueous phase D containing impurities and an organic phase D containing liquid polycarbonylsilane. Step 4: Then, the organic phase D containing liquid polycarbosilane obtained by phase separation is passed into the drying kettle 6 and dried with anhydrous magnesium sulfate. After being filtered through an organic filter membrane with a pore size of 0.45 μm in the filter kettle 7, it is finally passed into the distillation kettle 8 and distilled at 70℃ and a vacuum of 0.099 MPa for 60 min to obtain high-purity liquid polycarbosilane. The aqueous phases obtained from phase separation in steps 2 and 3 are collected and then successively neutralized with sodium hydroxide and treated in a high-gravity bed before being discharged.

[0028] Comparative Example The crude liquid polycarbosilane was extracted using the existing batch-type water washing extraction process, which involved seven repeated water washing extractions with a single batch processing cycle of 43 hours, to obtain liquid polycarbosilane.

[0029] Performance testing: The viscosity of the liquid polycarbosilanes obtained in Examples 2-4 and the comparative examples was determined using a rotational viscometer (25°C, 60 r / min). The ceramic yield of the liquid polycarbosilanes at 900°C was determined using a thermogravimetric analyzer (TGA). The total impurity content of magnesium, lithium, and aluminum in the liquid polycarbosilanes was determined using inductively coupled plasma mass spectrometry (ICP-MS).

[0030] The liquid polycarbosilanes obtained in the various embodiments and comparative examples were used to prepare ceramic matrix composites using the precursor impregnation pyrolysis (PIP) method. The preparation process generally involves immersing a carbon fiber preform into liquid polycarbosilane, applying vacuum and pressure to allow the liquid polycarbosilane to fully penetrate into the gaps between the fiber bundles, allowing it to stand, removing it, draining off excess liquid, and then placing it in a high-temperature furnace under argon protection and heating it to 1300°C. The liquid polycarbosilane undergoes pyrolysis and polycondensation, thereby transforming into a silicon carbide ceramic matrix. Finally, the above impregnation-pyrolysis process is repeated 10 times to gradually increase the density of the composite material, ultimately obtaining a dense ceramic matrix composite material.

[0031] The obtained ceramic matrix composite material was prepared into specimens of 3mm×4mm×36mm with a span of 30mm according to GB / T 6569-2006 "Test Method for Bending Strength of Fine Ceramics". The three-point bending loading rate was 0.5 mm / min, and the bending strength was tested in a universal testing machine. The ceramic matrix composite material was placed in a high-temperature furnace and heated to the target temperature under argon atmosphere. After holding at the temperature, the three-point bending test was immediately performed. When the bending strength dropped to 50% of the room temperature strength, the corresponding temperature was the effective high-temperature resistance temperature of the material. The cross-section of the specimen was observed by scanning electron microscopy (SEM), and the number and size distribution of defects such as pores and cracks were counted.

[0032] Table 1. Performance of liquid polycarbosilane obtained from each embodiment and comparative example.

[0033] As shown in Table 1, the overall performance of Examples 2-4 is significantly better than that of the comparative examples. Furthermore, the reduced total impurity content of liquid polycarbosilane significantly improves the flexural strength and high-temperature resistance of SiC ceramic matrix composites. The comparative examples, due to their high impurity content, exhibit the worst performance in all aspects. This verifies that the viscosity and total impurity content of liquid polycarbosilane are significantly correlated with the ceramic yield, flexural strength, and high-temperature resistance of the material. Low impurity content and suitable viscosity are key to the preparation of high-performance SiC ceramic matrix composites using polycarbosilane.

[0034] The above embodiments are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A method for purifying liquid polycarbosilane, characterized in that: Includes the following steps: Step 1: First, preheat the crude liquid polycarbosilane to 30~40℃; Step 2: Then, the preheated liquid polycarbosilane is mixed with the purifying agent and stirred for 30-60 min at a temperature ≤0℃ and a stirring rate of 150-200 r / min. After standing for 30-60 min, the phases are separated to obtain an aqueous phase A containing impurities and an organic phase A containing liquid polycarbosilane. The purifying agent includes a hydrocarbon organic solvent with a boiling point below 120°C and dilute hydrochloric acid, wherein the mass ratio of the hydrocarbon organic solvent to the dilute hydrochloric acid is 1:3 to 1:10, and the mass ratio of crude liquid polycarbosilane to the purifying agent is 1:1 to 1:

3. Step 3: Then, the organic phase A obtained by phase separation is mixed with dilute hydrochloric acid and stirred for 10-30 min at a temperature ≤10℃ and a stirring rate of 150-200 r / min. After standing for 10-30 min, phase separation is performed to obtain an aqueous phase B containing impurities and an organic phase B containing liquid polycarbosilane. The mass ratio of organic phase A to dilute hydrochloric acid is 1:1 to 1:

3. Step 4: Repeat step 3 2-3 times, then dry the organic phase containing liquid polycarbosilane obtained by phase separation with anhydrous magnesium sulfate, filter it through an organic filter membrane, and finally distill it at 60-80℃ and 0.095-0.1 MPa for 30-60 min to obtain high-purity liquid polycarbosilane.

2. The purification method for liquid polycarbosilane according to claim 1, characterized in that: In step 2, the hydrocarbon organic solvent is n-pentane, n-hexane, n-heptane, and petroleum ether.

3. The method for purifying liquid polycarbosilane according to claim 1, characterized in that: In step 2, the concentration of the dilute hydrochloric acid is 2~3 mol / L.

4. The purification method for liquid polycarbosilane according to claim 1, characterized in that: In step 3, the concentration of the dilute hydrochloric acid is 0.5~1 mol / L.

5. The method for purifying liquid polycarbosilane according to claim 1, characterized in that: In step 4, the pore size of the organic filter membrane is 0.45 μm.

6. A purification apparatus based on the purification method for liquid polycarbosilane as described in claim 1, characterized in that: The apparatus includes a heating vessel for preheating crude liquid polycarbosilane, a first-stage mixing chamber for mixing the preheated liquid polycarbosilane with a purifying agent, a first-stage phase separation chamber for separating aqueous phase A and organic phase A, a second-stage mixing chamber for mixing organic phase A with dilute hydrochloric acid, a second-stage phase separation chamber for separating aqueous phase B and organic phase B, a drying vessel for drying, a filtering vessel for filtration, and a distillation vessel for distillation, all connected in sequence.

7. The purification equipment according to claim 6, characterized in that: A third-stage mixing chamber and a third-stage phase separation chamber are sequentially connected between the second-stage phase separation chamber and the drying kettle.

8. The purification equipment according to claim 7, characterized in that: A fourth-stage mixing chamber and a fourth-stage phase separation chamber are sequentially connected between the third-stage phase separation chamber and the drying kettle.

9. A purification apparatus according to claim 8, characterized in that: The heating kettle, the first mixing chamber, the second mixing chamber, the third mixing chamber, the fourth mixing chamber, and the drying kettle are all equipped with stirring devices.

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